Colossal Biosciences Inc. is an American biotechnology and genetic engineering company working to de-extinct several extinct animals, including the woolly mammoth, the Tasmanian tiger, the dire wolf, the dodo, the moa and the bluebuck. In 2023, it stated that it wants to have woolly mammoth hybrid calves by 2028, and wants to reintroduce them to the Arctic tundra habitat. Likewise, it launched the Tasmanian Thylacine Advisory Committee, a thylacine research project to release Tasmanian tiger joeys back to their original Tasmanian and broader Australian habitat after a period of observation in captivity.
The company develops genetic engineering and reproductive technology for conservation biology. It was founded in 2021 by Harvard geneticist George Church and billionaire entrepreneur Ben Lamm. It is based in Dallas, Texas.
History Foundation In a 2008 interview with The New York Times, George Church first expressed his interest in engineering a hybrid Asian elephant-mammoth by sequencing the woolly mammoth genome. In 2012, Church was part of a team that pioneered the CRISPR-Cas9 gene editing tool, through which the potential for altering genetic code to engineer the envisioned "mammophant" surfaced. Church presented a talk at the National Geographic Society in 2013, where he mapped out the idea of Colossal.
Church and his genetics team used CRISPR to copy mammoth genes into the genome of an Asian elephant in 2015. That same year, Church's lab integrated mammoth genes into the DNA of elephant skin cells; the lab zeroed in on 60 genes that experiments hypothesized as being important to the distinctive traits of mammoths, such as a high-domed skull, ability to hold oxygen at low temperatures, and fatty tissue. Church's lab reported in 2017 that it had successfully added 45 genes to the genome of an Asian elephant.
In 2019, Ben Lamm, a serial entrepreneur, contacted Church to meet at his lab in Boston. Lamm was intrigued by press reports of Church's de-extinction idea.
Launch Colossal was officially launched on September 13, 2021. The launch included a $15million seed round led by Thomas Tull, Tim Draper, Tony Robbins, Winklevoss Capital Management, Breyer Capital, and Richard Garriott. In addition to the de-extinction of the woolly mammoth, Colossal, in partnership with Dr. Paul Ling of Baylor College of Medicine, hopes to develop a vaccine to the elephant endotheliotropic herpesvirus, a virus which infects and kills many young Asian elephants.
Colossal also announced that the company's mission was to preserve endangered animals through gene-editing technology and use those same animals to reshape ecosystems to combat biodiversity loss.
The company's genomic modeling software development could potentially bring forth advancements in disease treatment, multiplexed genetic engineering, synthetic biology, and biotechnology. Colossal recruited mammoth and modern elephant experts Michael Hofreiter and Fritz Vollrath, as well as bioethicists R. Alta Charo and S. Matthew Liao for their consultation. Other scientific advisory board members include: Carolyn Bertozzi, Austin Gallagher, Kenneth Lacovara, Helen Hobbs, David Haussler, Elazar Edelman, Joseph DeSimone, Erez Lieberman Aiden, Christopher E. Mason, and Doris Taylor. Colossal's team includes over 170 scientists and 95 advisors that specialize in fields such as genomics, paleontology and conservation.
In October 2021, Colossal announced its partnership with VGP; through this collaboration, Colossal will provide funding for VGP to sequence and assemble Asian, African bush, and African forest elephant genomes for preservation purposes. These genomes were made publicly accessible for research without use restrictions in July 2022 and May 2023, respectively.
In March 2022, Colossal raised $60million in a Series A funding round led by Thomas Tull, bringing the total funding to $75million. Other participants in this funding were Untamed Planet, Animoca Brands, Breyer Capital, Animal Capital, Arch Ventures co-founder Robert Nelsen, Paris Hilton, Bold Capital, First Light Capital Group, Boost VC, Jazz Ventures, Builders VC, Green Sands Equity, Draper Associates, and Charles Hoskinson.
Colossal spun out its software platform, Form Bio, in September 2022 with $30million in funding. Lamm has stated that Colossal is run like a software company, and monetization will stem from technologies developed by the company. Form Bio has developed an AI-based software platform designed to help scientists manage large and complicated datasets.
In January 2023, Colossal completed a Series B funding round, raising an additional $150million and putting the company's valuation at over $1billion. The same month, Colossal launched its Conservation Advisory Board, which includes Forrest Galante, Iain Douglas-Hamilton, Mead Treadwell, and Aurelia Skipwith as its members.
In October 2024, Colossal announced $50million in funding for its launch of the Colossal Foundation.
The company secured $200million in Series C funding in January 2025, bringing its total valuation to $10.2billion and making it Texas' first decacorn. With the new funding, Colossal announced its intention to expand its work in artificial wombs and de-extinction species. As of January 2025, Colossal has raised $435million in total funding since its foundation.
In August 2025, Colossal announced, Colossal Australia, its first expansion outside the United States with its acquisition of the Thylacine Integrated Genomics Restoration Research Lab (TIGRR) at the University of Melbourne. The lab is led by the well-known Australian scientist, and Colossal chief biology officer, Andrew Pask.
In November 2025, Colossal announced that it had acquired animal cloning company Viagen.
Science and technology Colossal is the first company to apply CRISPR technology to species restoration efforts. Its lab pairs CRISPR/Cas9 with other DNA-editing enzymes, such as integrases, recombinases, and deaminases, to splice woolly mammoth genes into the Asian elephant, and has "used 65 different mammoth genomes across about 700,000 years to create an assembled ancient DNA genome".
In July 2022, VGP and Colossal announced that they successfully sequenced the entire Asian elephant genome; this was the first time that mammalian genetic code had been fully sequenced to a detailed level since the Human Genome Project was completed in the early 2000s.
Breaking, a plastic degradation and synthetic biology startup, was developed inside Colossal and launched in April 2024. The startup discovered X-32, a microbe that is capable of breaking down various plastics in as little as 22 months while leaving behind carbon dioxide, water and biomass.
It was reported in 2024 that Colossal successfully produced the first-ever elephant and dunnart iPSCs.
The Colossal Biovault collects tissue samples of endangered species in hopes to allow cell lines to become accessible and stored in domestic partner facilities. Its first projects included the Sumatran rhinoceros, the red wolf, the northern quoll, the northern white rhinoceros, the pink pigeon, the tooth-billed pigeon, the Victorian grassland earless dragon, the vaquita, the African bush elephant, the African forest elephant, the Asian elephant, and the ivory-billed woodpecker. In addition to these species, Colossal planned to biobank the "top 100 most imperilled" species on their Colossal 100 list. However, this list has not been publicly disclosed.
In October 2024, the company announced that it had rebuilt a 99.9% accurate genome of the thylacine, using a "pickled" 110-year-old fossilized Tasmanian tiger skull. This marks "the most complete ancient genome of any species known to date" and provides a full DNA blueprint to potentially bring back the Tasmanian tiger. Three months later, in January 2025, the company sequenced the complete genome of the Tasmanian tiger; Colossal also made a prototype for an artificial uterus and used that to culture fertilized single-cell marsupial embryos to over halfway through pregnancy.
In March 2025, Colossal announced the creation of gene-edited "woolly mice" with mutations inspired by woolly mammoths, touting it as a step toward engineering mammoth-like Asian elephants. The mice, which exhibit long, shaggy, tawny-toned fur, were developed using a mix of mammoth-like and known mouse hair-growth mutations. Some experts expressed skepticism, arguing that the experiment was more about mouse genetics than a breakthrough in de-extinction. The company stated that it planned further studies on the mice's cold tolerance and long-term health but had no commercial breeding plans.
In April 2025, the Colossal Biosciences Dire Wolf Project was announced, which used cloning and gene-editing to birth three genetically modified wolf pups: six-month-old males Romulus and Remus and two-month-old female Khaleesi. In-house scientists analyzed the dire wolf genome, extracted from two ancient samples – a 13,000-year-old tooth and a 72,000-year-old ear bone. After comparing the genomes of gray wolves and dire wolves to identify the genetic differences responsible for the dire wolf's distinctive features, Colossal isolated EPC cells from gray wolf blood samples before rewriting 14 key genes in the cell's nucleus to express 20 traits claimed to represent the dire wolf phenotype. Overall, the work was less invasive than the typical cloning process. Colossal scientists produced 45 engineered ova, which developed into embryos and inserted into the wombs of two surrogate hound mixes. Colossal claims that these minor genetic modifications effectively revived dire wolves as a species, though "no ancient dire wolf DNA was actually spliced into the gray wolf's genome".
Independent experts disagreed with Colossal Biosciences' claim that these animals are revived dire wolves, stating that they are "not a dire wolf under any definition of a species ever". The IUCN Species Survival Commission Canid Specialist Group officially declared that the three animals are neither dire wolves nor proxies of the dire wolves based on the IUCN SSC guiding principles on creating proxies of extinct species for conservation benefit. They commented that creating phenotypic proxies doesn't change the conservation status of an extinct species and may instead threaten the extant species such as grey wolves. Therefore, since the claimed proxies do not conform with the IUCN SSC guidelines, have no ecological niche left today and "will not restore ecosystem function", they concluded that the Colossal Biosciences' project "does not contribute to conservation." Colossal Biosciences released a clarifying document Alignment of Colossal’s Dire Wolf De-Extinction Project with IUCN SSC Guiding Principles in response.
In May 2025, the company's chief scientist Beth Shapiro stated that the three animals are merely "grey wolves with 20 edits" as purportedly stated by the company "from the very beginning", acknowledging that it is impossible to bring back an extinct organism, or at least an organism "identical to a species that used to be alive". She admitted that the term "dire wolves" applied to the pups are a colloquialism, not scientific terminology.
In the same month, Colossal along with University of Melbourne announced that they have successfully created vital stem cells for the thylacine, with researchers estimating they could be re-introduced in the wilderness in as little as 8 years.
Development Because the woolly mammoth and Asian elephant share 99.6% of the same DNA, Colossal aimed to develop a proxy species by swapping enough key mammoth genes into the Asian elephant genome. Key mammoth genetic traits include a 10-centimeter layer of insulating fat, five different types of shaggy hair, and smaller ears to help the hybrid tolerate cold weather.